In a conventional connection system, in applications in automotive engineering, an electrical or electronic control unit is connected to a plug connector of a cable harness of the motor vehicle. In such applications, first electrical terminals are situated in parallel to one another within a terminal area of the device with the aid of a first positioning device. In particular, the electrical terminals are formed as pin-shaped tag connectors. For contacting using appropriate second electrical terminal elements, in particular in the form of socket-type elements, the second terminal elements are aligned in parallel to the first electrical terminals in a plug connector housing of the cable harness plug with the aid of a second positioning device. When the electrical terminals are connected, it is essential for them to be guided together in their correct position to one another, and held in fixed position during the connecting, in order to establish a secure electrical connection over the entire period of operation of the electrical device. This is achieved with the aid of the mentioned positioning devices, which fix the first and the second electrical terminals in both their axial direction and in their horizontal plane (in relation to the longitudinal axes of the terminal elements), for example, by a clamping connection or by insert molding using the material of the particular positioning device.
Depending on the use of the device, there are typically two different configurations, in which either a connection is required between the device and the plug connector unit which is sealed against environmental influences, or a connection in which leak tightness is not required. Typically, tight systems are always required when, due to the installation location or the conditions of use, the entry of moisture or dirt into the area between the electrical terminals is to be avoided, in order to be able to constantly protect the electrical connection securely and reliably. For this reason, conventionally, a connection system is formed in such a way, that in addition to the second positioning device in the plug connector unit (cable harness plug connector), a sealing element is situated on the side facing the first terminals in the electrical or electronic device, which ensures the necessary leak tightness. Such a sealing element is known as a so-called “sealing mat” and simultaneously includes guidance properties for the second connecting elements, in order to bridge the axial distance between the positioning devices. It is also customary in such a connection system to provide an additional, in particular, radially circumferential sealing element between the device and the plug connector unit, which seals the connection area between the above-named components. If for reasons of standardization and/or cost, it is intended to use the conventional connection system also for connection systems, in which a certain leakiness is allowed, it is thus not possible to use it by simply omitting the sealing element (sealing mat), since the elimination of the sealing element would make the axial distance between the two positioning devices so great that an unambiguous positioning of the second electrical terminals within the plug connector unit is no longer ensured. This results in the risk that the electrical terminals would no longer be positioned in relation to one another with sufficient precision when being connected.